Door operator



Sept. 9, 1958 w. KLAMP 2,851,266

DOOR OPERATOR Filed July 13, 1956 2 Sheets-Sheet 1 5 78 INVENTOR.

VV/LL/AM KLAMP M W. KLAMP DOOR OPERATOR Sept. 9, 1958 2 Sheets-Sheet 2 Filed July 13, 1956 IN V EN TOR. lV/LL/AM KLAMR i Arron/vars UnitedStatesPatent O 2,851,266 I noon OPERATOR William rom Rocky River, Ohio Application July 13, 1 956, Serial No. 597,617 is Claims. Cl. 268-59) I The present invention relates to operating mechanisms and, more particularly, to operators for opening and closing garage doors, and the like, especially overhead doors.

conventionally, door operators, which comprise a carriage operated by an endless chain, have been provided for opening and closing doors, or similar closures, particularly overhead garage doors. Usually, the chain is driven by a reversible motor which operates in one direction to open the door, and is reversed and operates in the opposite direction to close the door, the carriage being connected to the chain and movable therewith. The carriage may be supported by a member extending along the chain and a link interconnects the carriage and the door. One of the problems with the conventional chain-type of door operator is that when a large door is being operated, the chain must be tensioned considerably in order to prevent sag therein placing a stress on the bearing members for the sprockets, or the like, which rotatably support the chain. This materially reduces bearing life and makes it necessary to frequently service the operator. The conventional operator is also a noisy mechanism and can often be heard for relatively great distances.

The use of a reversible motor in the conventional operator presents problems when a fault in the electrical control system causes the motor to operate continuously to open and close the door. The continual reversing of the motor will quickly cause an overheated condition and, if not corrected in a relatively short period of time, will require replacement of the motor. In addition to being objectionable when such a fault occurs, a reversible motor is considerably more expensive than a motor of the non-reversing type.

In addition to the above problems, most of the conventional door operators utilize a load-responsive clutch which will release when the load thereon exceeds a predetermined amount. Such a clutch is provided so that the drive connection to the door will be discontinued in the event the door strikes an object while closing. This type of clutch requires constant servicing and is objectionable in that the load of the door will vary under normal conditions, whereby making it impossible to provide a load-responsive clutch which is sensitive to light pressures. While some door operators are arranged so that when the door strikes an obstruction the motor is stopped, none of the arrangements are simple, and many require the use of a flexible electrical connection between the door itself and the stationary part of the door operator. Such a connection is objectionable from a safety standpoint.

The principal object of the present invention is to provide a new and improved simple, reliable and noiseless operator for closures such as garage doors, particularly the overhead type, which shall be economical to manufacture, readily installable, and give long life with little maintenance or servicing.

Another object of the present invention is to provide r 2,851,266 Q PateritedSept. 9, 1958 ICC in a motor driven door operator of the type in which the door is connected, by means including a link, to a carriage reciprocated to open and close the door, a new and improved control system wherein the door closing movement is stopped by relative movement between the link and carriage occasioned by the door meeting an obstructing force during its door closing movement.

Another object is, to provide ,a motor driven door operator of the type referred to in which the control circuit for the motor includes a conductor extending along the path of movement in the carriage and wherein relative movement betweenthe link and the carriage which occurs when the door meets 'an obstructing force during its closing movement effects the movement of a part on the carriage relative to the conductor to engage or disengage the conductor to thereby make or break a control circuit forthe motor.

Yet another object of the present invention is to provide a new and improved door operator for garage doors, and the like, wherein an endless chain, which isdriven to reciprocate a carriage connected to the door, has an element which is engageable with a first part on the carriage for moving the carriage in one direction to open or close the door, and which loses connection with the carriage upon reversal of direction and is engageable with a second part of the carriage'to move the latter in the opposite direction.

A further object of the present invention is to provide a door operator in which a chain, which is driven to open and close the door, is supported throughout its length upon a member which, preferably, also supports the carriage driven by the chain and to which the door being operated is connected.

A further important object of the present invention is to provide an operator which is so arranged that the door closing movement of the operator will be stopped in response to slight pressure on the door, or closure, by

an obstruction in the path thereof without the use of load-' responsive clutches or flexible electrical connections to the door.

The present invention also has, as one of its objects, the provision of a novel operator for garage doors, and the like, wherein an obstruction in the path of the door will cause relative movement between two conductive members to short-circuit a relay which is energizable to complete a circuit for energizing the motor.

It is still another object to provide a new and improved operator for a closure member in which an uninsulated conductor extends along the path of the carriage reciprocated to open and close a closure member and which is engaged by a part of the connection between the carriage and the closure member when the closure member strikes an obstruction to complete a circuit for stopping the operation of the carriage, the conductor preferably forming part of a low voltage control circuit for a motor for driving the carriage.

It is still further an object of the present invention to provide a new and improved operator for a garage door which includes means for turning on a light immediately after the door starts to open and for turning off the light only when the door is substantially closed and in which the means comprises a toggle rod supported adjacent the path of the carriage reciprocated to operate the door.

A further object is to provide an operator having the above-mentioned features and which is assembled into a unit ready for installation.

The present invention resides in certain constructions and arrangements of parts, and further objects and advantages thereof will be apparent from the following detailed description of the preferred embodiment made with reference to the accompanying drawings forming a 3 part of this specification for all matter shown therein, whether or not expressly described, and in which:

Fig. 1 is a fragmentary perspective view of the interior of a garage having a garage door which is opened and closed by an operator constructed in accordance with the present invention;

Fig. 2 is a plan view of the operator shown in Fig. 1;

Fig. 3 is a side elevational view of the operator shown in Fig. 2;

Fig. 4 is a sectional view taken approximately along line 44 of Fig. 3 and looking in the direction of the arrows; and

Fig. 5 is a simplified circuit diagram for controlling the motor of'the operator.

The present invention is susceptible oj various constructions and modifications and of e'with various closures, and the like, which are to operated between two diiferent positions, but is particularly advantageous when embodied in an operator for opening and closing an overhead door, such as those conventionally used in garages. The present invention contemplates the provision of an operator which comprises a carriage which is reciprocated along a path to open and close a door connected thereto by means including a link which is moved relative to the carriage when the door meets an obstructing force during its door closing movement and control means responsive to the movement of the link when the door closing movement is opposed to control the door closing operation. In the preferred embodiment the movement of the link relative to the carriage occasioned by the door meeting an obstructing force causes a part associated with the carriage to engage an uninsulated conductor extending along the path of the carriage, the part and conductor forming a part of the control circuit for the motor. The present invention also contemplates the provision of an operator wherein the carriage is reciprocated by an endless chain which is driven in one direction only and which carries an element that is engageable with the carriage as the element travels in one direction along the path to move the carriage in one direction and which loses contact with the carriage upon its reversal of direction to travel in the opposite direction along the path and engages a different part of the carriage when moving in the opposite direction to move the carriage in its opposite direction. Furthermore, the present invention contemplates the provision of support means for the chain so that the chain need not be tensioned.

Referring to Fig. 1, a garage is provided with a door 11 of the overhead. type for closing an opening in a wall 10a of the garage and which is operable between an open and closed position by means of an operator 12 suspended overhead. The door 11 is supported and guided in its overhead movement by tracks 13 located at each of the opposite ends of the door and in which rollers 14, carried by the door, operate. The door is preferably counterbalanced by tension springs 15 connected to the door through cables 16. The door and its supporting structure are of conventional construction and, per se, form no part of the present invention and, therefore, have not been shown, or will not be described in detail.

The operator 12, for opening and closing the door 11 is supported above the door and comprises a carriage 17 connected to the door by a link 18 and supported for movement to open and close the door by an inverted T- shaped rail 20. The rail 20 extends horizontally along the path that the door moves when it is being opened or closed and is connected, at its outer end adjacent the door opening, by a bracket 21 to the wall 10a of the.

garage. The other, or inner, end of the rail 20 is supported from the ceiling of the garage by a strut 22 welded or otherwise secured to a support member 22a forming an extension of the rail 20.

In the preferred embodiment, the underside of the carriage 17 comprises two side-by-side L-shaped plates 23 having horizontal legs 24 forming the bottom of the car- 4 riage, and vertical legs 25 depending from the inner ends of the horizontal legs 24. The vertical legs 25 are 11011- zontally spaced from each other and the link 18 is re- .ceived therebetween and is connected thereto by a bolt 26. The bolt 26 passes through the legs 25 and through an elongated slot 27, best shown in Fig. 3, in the link 18, the slot 27 permitting endwise movement of the link 18 relative to the carriage 17 and the bolt 26. A spring 28 is positioned between a collar 29-on the link 18, and the lower edges of the depending legs 25 of the plates 23, and exerts a biasing force which normally urges the link 18 to a position where the upper end of the slot 27 is in engagement with the bolt 26. The purpose of the elongated slot 27 will be explained in more detail hereinafter.

The inverted T-shaped rail 20 has horizontal flange portions 30, 30a upon which the carriage 17 slides. Each of the horizontal leg portions 24 of the plates 23 support two fiber bearing members 31, 32 for engaging the upper and lower surfaces, respectively, of the adjacent horizontal flanges 30, 30a. The bearing members 31, 32 engaging the flange 30 are spaced by a plate 33 and the bearing members adjacent the flange 30a are spaced by a plate 34. The fiber-bearing members 31, 32 provide a relatively noiseless low fritcion sliding contact between the rail 20 and the carriage 17. Each leg portion 24 is connected with the bearing members and spacer plate therefor by bolts 35.

The carriage 17 is moved along the rail 20 to open and close the door 11 by the operation of a motor 36 which drives an endless chain 37 supported between sprockets 38, 39 at the opposite ends of the rail 20. The chain 37 has runs 41, 42 located on opposite sides of the vertical leg 43 of the rail 20. When the chain is rotated in one direction, the runs 41, 42 are moving in opposite directions. When the door is to be opened, the carriage 17 is connected to the run 42, and when the door is to be closed, the carriage is connected to the run 41.

To connect the carriage 17 with the chain 37. the chain carries a pin 45 which is engageable with either a block 46 positioned adjacent the run 41, or a block 47 adjacent the run 42. The blocks 46, 47 are supported on extended portions 48, 49 of the plates 33, 34, respectively. The portion 48 of the spacer member 33 extends outwardly of the adjacent bearing members 31, 32 in the direction of movement of the carriage 17 when the door is being closed, that is, toward the sprocket 38, while the portion 49 of the member 34 extendsin the opposite direction from the adjacent bearing members 31, 32, that is in the direction the carriage moves when the door is being opened, which is in a direction toward the sprocket 39. As the door operator is viewed in Fig. 2, the door 11 is not quite in a fully closed position, and the pin 45 is in engagement with the block 46 and is just beginning to move around the sprocket 38. As is best shown in Fig. 2, the block 46 is a generally horizontal block which extends over the chain 37 and is of a generally U-shaped configuration having spaced horizontal projections 51, 52 separated by a notch 53. When the pin 45 is in driving engagement with the block 46, the pin is positioned between the projections 51, 52 and is in engagement with the inner side of the projection 52 to cause movement of the block. As is shown in the drawing, the inner sides of the projections 51, 52 extend at right angles to the runs 41, 42 so as not to produce a camming action on the pin. The projection 51 is shorter than the leg projection 52 and its outer side is curved to provide a cam surface 54 for reasons which will appear hereinafter.

As the chain 37 is rotated, the pin 45 will first complete the closing of the door and will then, by moving around the sprocket 38, lose engagement with the projection 52 and begin moving in the opposite direction. As

the pin moves along the run 42, it will engage the block. 47 which is similar in construction to the block 46 and the parts thereof will be given the same reference numeral as the corresponding parts of block 46. The pin 45 will first engage cam surfzce 54' on a projection 51' of the block 47, which projection extendsover the chain 37, and will ride the cam surface 54' to move by the projection 51' into a notch 53 and into engagement with the inner side of a projection 52', the projection 52' is, like the projection 52, longer than the projection 51. The inner side of projection 52 extends perpendicularly to the run 42 and the pin will not move thereby and will cause the carriage 17 to move with the chain 37 in the direction necessary to open the door. The cam surface 54 on the cam block 46 functions in the sam /manner as the cam surface 54. The carriage 17 ,wiljcbntinue to move with the chain 37 and the pin. 4' ntil the pin moves away from the block 47 a moves around sprocket 39. When the pin moves aiv ay from the block, the door will be in its fully open position. It will be noted that by positioning the pin in a notch between two projections, run-ahead of the door is prevented when the latter is being closed.

It can now be seen that the relative positions of the blocks 46, 47 and the sprockets 38, 39 are such that when the door 11 is in its closed position, the block 46 is immediately adjacent to the sprocket 38, and when the door is in its open position, the block 47 is adjacent the sprocket 39. The distance which the carriage moves in opening or closing the door may be adjusted by adjusting the position of the blocks 46, 47 along the portions 48, 49 of the spacer members 33, 33a to vary the point at which the pin 45 picks up the blocks. To this end, the portions 48, 49 are provided with a plurality of holes 55 which may be used in securing the blocks 46, 47 to their respective portions.

In the preferred embodiment, the block 46 is connected to its supporting portion 48 by a resiliently expansible pin 56 and a spring-biased bolt 57 which pass through spaced openings in the portion 48 and in the block 46. The pin 56 may be withdrawn from the openings through which it passes by merely pulling. The block 57 has a head in engagement with the upper side of block 46 and a nut threaded onto the lower end of the bolt, as it is viewed in Fig. 3, with a spring 58 interposed between the nut and the underside of the portion 48. The spring 58 permits movement of the block 46 relative to the support portion 48 for reasons which will appear hereinafter.

The motor 36 for driving the operator is supported by the member 22a forming an extension of the rail 20 and is connected to the sprocket 39 by a belt drive 62. The belt drive 62 includes a pulley 63 mounted on the lower end of the motor shaft, and a pulley 64 fixed to the lower end of a vertical shaft 65. The sprocket 39 is fixed to the upper end of the shaft 65, and rotation of the pulley 64 causes rotation of the sprocket 39. The necessary gear reduction can be obtained through the belt drive 62, or intermediate gearing between the belt drive and the sprocket 39 may be provided if desired. The motor 36, in the illustrated embodiment, is controlled by a wall switch 66, shown schematically in the circuit diagram of Fig. 5, and by a limit switch 67 mounted on the rail 20 at the beginning of the run 41 adjacent to the pulley or the sprocket 39. The wall switch 66 is a threeposition switch having a neutral position, a start position, and a stop position and when released always returns to its neutral position. When the switch is moved to its start position, a low voltage control circuit is completed for energizing a relay 68, having normally open contacts 74 7|, from a step-down transformer 72 having its primary. connected across the normal line voltage and a low voltage secondary, for example 6.3 volts. The closing of contacts 70 upon energization of relay 68 completes a circuit to supply normal household line voltage to the motor 36, while the closing of contacts 71 completes a holding circuit for relay 68. When the switch 66 is moved to its stop position, it completes a circuit which shorts out the coil of relay 68 including the holding cir- The limit switch 67 is connected parallel with the coil of relay 68, and when closed, short-circuits the coil in the same manner as the stop position of the switch 66 to cause deenergization of the coil and the stopping of the motor. The chain 37 is provided with switch-operating members 73, 74 for operating the limit switch 67. The operating member 73 stops the motor 36 upon completion of the door closing movement and is mounted on the chain 37 so that it will operate the limit switch 67 just after the pin 45 loses contact with the block 46. The switch-operating member 74 stops the motor 36 upon completion of the door opening movement and is so positioned on the chain that it engages the switch 67 just after the pin 45 loses contact with the block 47.

One of the features of the present invention is the provision of novel meansfor stopping the door closing operation of the motor 36 whenever the door strikes an obstruction in its closing movement. According to this feature of the present invention, an uninsulated cable 75 extends along the underside of the rail 20 and passes, with clearance, between the spaced plates 23 of the carriage 17. 10a is supported by an insulator 76 fixed to the rail 20, and the other end of the cable is supported by an insulator, not shown in the drawing, and is connected to the hot side of the secondary of the transformer providing the low control voltage, the other sideof the transformer secondary being grounded. When the door meets an obstruction, the link 18 will move upwardly against the bias of the spring 28 and will engage the cable 75 grounding the cable to effect a control operation. In the preferred embodiment, grounding of the cable 75 completes a circuit to short-circuit the coil of relay 68. When the relay coil is short-circuited, the motor will stop and the holding circuit for the relay will be broken. The pressure required to move the link 18 into engagement with the cable 75 is only a slight pressure and, therefore, an extremely sensitive safety means is provided.

If the power should fail while the door is being operated, the door may be operated manually by disconnecting the block which is in engagement with the pin 45. The block 46, for example, may be disconnected from the pin 45 by pulling the pin 56 and pivoting the block about the bolt 57. This will swing the leg portion 52 out of the path of the pin 45 and allow the door to be moved manually to either of its positions.

Another feature of the present invention is the provision of means for turning a light on and off as the door is respectively opened and closed. To this end, a toggle bar 78 is rockably supported from the center leg 43 of the rail 20 in a position above the chain 37. The toggle rod 78 has arms 79, 80 extending outwardly therefrom at its opposite ends. The arm 80 is at the end of the toggle bar remote from the motor 36 and is engageable by a cam member 81 carried by the block 46. The toggle rod 78 is rockably supported by the rail 20 and when the cam member 81 passes under the arm 80, the latter is moved upwardly and then downwardly to its initial position to rock the rod and move the toggle arm 79. The arm 79 of the toggle rod 78 is connected to a chain 82 for operating a light switch. The switch is positioned within a housing 83 which also encloses the relay 68 and supports a light socket 84for the garage light. As shown in the drawings, the arm 80 is located so that the cam member 81 will actuate it as soon as the door starts to open, and so that, when the door is being closed, the cam member will not engage it until the door is substantially closed. This assures that the light is turned on in the garage immediately after the door starts to open and will stay on until the door is closed, making it difficult, if not impossible, for an unau- The end of the cable 75 adjacent the wall thorized person or intruder to slip into the garage while the door is being operated.

From the above, it can be seen that the present invention provides a simple, reliable and noiseless operator for closures such as garage doors, and the like, and that the objects heretofore enumerated and others have been accomplished. An operator constructed according to the present invention does not require the use of a reversible motor and may be so constructed as to be extremely sensitive to additional load imposed on the operator by reason of the door engaging an obstruction in its path. Furthermore, the means for stopping the door, when it strikes an obstruction, is extremely simple and does not require flexible electrical connections to the door itself. Also, a door embodying features of the present invention may be constructed so as to be readily adapted to accommodate various-size garage doors and may include an extremely simple mechanism for actuating a light switch to turn on the light immediately when the closure begins to open, and to turn off the lights only when the closure is in a substantially closed position.

While a preferred embodiment of the present invention has been described in considerable detail, it is hereby my intention to cover all modifications, constructions and arrangements which fall within the ability of those skilled in the art and the scope of the appended claims.

Having thus described my invention, I claim:

1. An operator for a closure member comprising a carriage movable in opposite directions along a path to respectively open and close the closure member, a motor, means operatively connecting said motor to said carriage to reciprocate the latter along said path, a link interconnecting said carriage and said closure member, means permitting relative movement between said carriage and said link when the closure member meets an obstruction during its closing movement, and an element engaged by said link upon a predetermined relative movement to condition an electric circuit to prevent the operation of said motor to close the door upon the engagement of said element and said link.

2. An operator as defined in claim 1 wherein said element is an uninsulated conductor extending along said path.

3. An operator for a closure member comprising a carriage movable in opposite directions along a path to relatively open and close the closure member, a motor for reciprocating said carriage along said path, a low voltage control circuit for said motor including a relay energizable and deenergizable to start and stop the motor, a link interconnecting said carriage and said closure member, means permitting relative movement between said linkand said carriage when said closure member meets an obstruction during its closing movement, and an element engaged by said link between a predetermined relative movement upon the link and carriage and operable to complete a short circuit about said relay when engaged by said link.

4. An operator as defined in claim 3 wherein said element is an uninsulated conductor extending along said path.

5. An operator for reciprocating a member between two positions comprising a carriage movable in opposite directions along a horizontal path, means operatively connecting said carriage to said member to move said member in opposite directions, an inverted generally horizontal T-shaped rail having a vertical center portion and horizontal flanges, means supporting said carriage on said flanges for movement therealong, a rotatable member adjacent each of the opposite ends of said rail, an endless chain extending about said rotatable members and having runs immediately above said flanges and on opposite sides of said center portion, said flanges supporting said runs, a drive pin carried by said chain, first and second members overlying said chain along said first and second runs respectively and drivingly engageable by said' pin when moving along the adjacent run, means adjustably connecting said first and second members to said carriage for adjustment along lines parallel to said runs, a toggle rod rockably supported by said center portion and extending along said rail and having an arm adjacent one end of said rail, means on said carriage for rocking said arm as the carriage moves along said rail, a switch supported adjacent the other end of said arm for energizing a light, means operatively connecting the other end of said toggle rod to said switch for actuating the latter upon rocking movement of said toggle arm, a motor for driving said chain in one direction, a member supporting said motor from the other end of said rail, and means operatively connecting said motor to said rotatable element adjacent said other end of said rail for driving the rotatable element.

6. An operator for operating a reciprocable member between two positions comprising a carriage movable in opposite directions along a substantially horizontal path, means operatively connecting said carriage to said member to move said member in opposite directions, an inverted generally horizontal T-shaped rail having a vertical center portion and horizontal flanges, means slidably supporting said carriage on said flanges for movement therealong, a rotatable element adjacent each of,

the opposite ends of said rail, an endless chain extending about said rotatable members and having runs immediately above said flanges and on opposite sides of said center portion, said flanges supporting the runs of said chain, a drive pin carried by said chain, first and second members overlying said chain along said first and second runs respectively and drivingly engageable by said pin when moving along the adjacent run, means connecting said first and second members to said carriage, a toggle rod rockably supported by said center portion and extending along said rail and having an arm adjacent one end of said rail, means on said carriage for rocking said arm as the carriage moves along said rail, a switch supported adjacent the other end of said rod for energizing a light, means operatively connecting the other end of said toggle rod to said switch for actuating the latter upon a rocking movement of said toggle arm, a motor for driving said chain in one direction, means supporting said motor from the other end of said rail, and means operatively connecting said motor to said rotatable element adjacent said other end of said rail for driving the rotatable element to drive said chain, and a control circuit for said motor including an uninsulated conductor member supported by and extending along said rail, said means interconnecting said carriage and said closure including a part movable relative to said carriage into engagement with said conductor member when said reciprocable member meets an obstruction when moving in one direction, and a circuit completed by the engagement of said part and said conductor member for preventing operation of said motor.

7. An operator for moving a reciprocable member between two positions comprising a carriage movable in opposite directions along a horizontal path, means operatively connecting said carriage to said member to move said member in opposite directions, an inverted generally horizontal T-shaped rail having a vertical center portion and horizontal flanges, fibrous bearing members slidably supporting said carriage on said flanges for movement therealong, a rotatable element adjacent each of the opposite ends of said rail, an endless chain extending about said rotatable members and having runs immediately above said flanges and on opposite sides of said center portion, said flanges supporting the runs of said chain, a drive pin carried by said chain, first and second members overlying said chain along said first and second runs respectively and drivingly engageable by said pin when moving along the adjacent run, means adjustably connecting said first and second members to said carriage for adjustment along lines parallel to said runs, a toggle rod rockably supported by said center leg and extending along said rail and having'an arm adjacent one end of said rail, means on said carriage for rocking said arm as the carriage moves along said rail, a switch supported adjacent the other end of said rod for energizing a light, means operatively connecting the other end of said toggle rod to said switch for actuating the latter upon a rocking movement of said toggle arm, a motor for driving said chain in one direction, a member supporting said motor and connected to the other end of said rail, means operatively connecting said motor to said rotatable element adjacent said other end of said rail for driving the rotatable element to drive said chain,

and a control circuit for said motor including an uninsulated conductor member supported by and extending along said rail, said means interconnecting said carriage and said closure including a part movable relative to said carriage into engagement with said conductor when said reciprocable member meets an obstruction when moving in one direction, and a circuit completed by the engagement of said part and said conductor for preventing operation of said motor.

8. An operator for a door comprising a carriage reciprocable in opposite directions along a path to respectively open and close the door, a motor operatively connected to said carriage to reciprocate the latter, and circuit means for controlling the operation of said motor when a predetermined force opposes the closing movement of said door comprising an electric conductor extending along said path and a movable conductive part associated with said carriage and movable to and from engagement with said conductor to make the break a control circuit for stopping the closing movement of said door and moved relative to said conductor in response to the closing movement of said door being opposed by said predetermined force.

9. An operator for a door comprising a carriage movable in opposite directions along a path to respectively open and close the door, a motor operatively connected to said carriage for reciprocating said carriage, a low voltage control circuit for said motor including a relay actuatable to control the operation of said motor and circuit means for energizing said relay and for actuating the relay when a predetermined force opposes the closing of said door, said circuit means including an uninsulated conductor extending along said path and a movable conductive member associated with said carriage and movable ,to and from engagement with said conductor to make and break a circuit for controlling the energization of said relay and operated relative to said conductor to actuate said relay in response to the closing movement of said door being opposed by said predetermined force.

10. An operator for a door comprising a carriage movable in opposite directions along a path to respectively open and close the door, a motor operatively connected to said carriage for reciprocating said carriage, a low voltage control circuit for said motor including a relay actuatable to control the operation of said motor and circuit means for actuating said relay when the door closing movement is opposed by a predetermined force, said circuit means including an uninsulated conductor extending along said path and a movable conductive means associated with said carriage and movable to and from engagement with said conductor to make and break a circuit for controlling the energization of said relay andmoved relative to said conductor to actuate said relay in response to the closing movement of said door being opposed by said predetermined force, the last said means including a link connecting said carriage to said door and means supporting said link for swinging movement relative to said carriage and for movement in a predetermined direction relative to said carriage in response to said predetermined force opposing the closing movement of said door.

11. An operator for opening and closing a door comprising a carriage reciprocable along a path, a motor for reciprocating said carriage, a link, means connecting said link to said door, means connecting said link to said carriage for swinging movement and for limited endwise movement relative to said carriage and including a spring connected between said carriage and said link and forming a force transmitting connection between said carriage and said link and yieldably urging said link endwise in one direction to close the door and yieldable to permit relative endwise movement in the opposite endwise direction between said carriage and said link when said door meets an obstruction in its closing movement, and means responsive to a predetermined relative movement in said opposite endwise direction between said link and said carriage against the action of said spring for stopping the door closing movement of said carriage.

12. An operator for opening and closing a door comprising a carriage operatively connected to said door and reciprocable in opposite directions along a path to respectively open and close the door, a motor operatively connected to said carriage for reciprocating said carriage along said path, means operatively connecting said carriage to said door comprising a link connected to said door and movable relative to said carriage and a spring connected between said carriage and said link and urging said link in a direction away from said carriage and toward said door, and circuit means for controlling the operation of said motor comprising a conductor extending along the path of said carriage and engageable to make a control circuit by a conductive part moved to and from engagement with said conductor in response to said relative movement between link and carriage and against the action of said spring.

13. An operator for opening and closing a door comprising a carriage reciprocable along a path, a motor for reciprocating said carriage, a link for connecting said door to said carriage for operation thereby, means connecting said link to said carriage and permitting limited relative movement with respect to said carriage comprising a spring forming a force transmitting connection between said carriage and said link and yieldably urging said link in a direction away from said carriage and toward said door and yieldable to permit said relative movement when said door meets an obstruction in its closing movement, and means responsive to a predetermined relative movement between said link and said carriage against the action of said spring for stopping the door closing movement of said carriage comprising an element supported adjacent said link and a part adjacent said element and moved to and from engagement with said element by said relative movement of said link and carriage.

14. An operator for opening and closing a door comprising a carriage reciprocable along a path, a motor for reciprocating said carriage, a link for connecting said door to said carriage for movement thereby, means conpecting said link to said carriage and permitting limited relative movement with respect to said carriage comprising a spring forming a force transmitting connection between said carriage and said link and yieldably urging said link in a direction away from said carriage and toward said door and yieldable to permit said relative movement when said door meets an obstruction in its closing movement, and means responsive to a predetermined relative movement between said link and said carriage against the action of said spring for stopping the door closing movement of said carriage comprising an uninsulated conductive member extending along said path and a conductive part moved by said link to engage and disengage said conductive member, said conductive member and said part being conductors of an electric control circuit for said motor.

15. An operator for opening and closing a door com- 1 for reciprocating said carriage, a'link for connecting said door to said carriage for movement thereby, means connecting said link to said carriage and permitting limited relative movement of said link with respect to said car- 12 moved to and from engagement with said conductor in response to said relative movement to selectively ground the conductor, said conductor and said conductive part forming a part of a low voltage control circuit for said riage comprising a spring forming a force transmitting 5 motorconnection between said carriage and said link and yieldable to permit said relative movement when said door meets an obstruction in its closing movement, and means responsive to a predetermined relative movement between said link and said carriage against the action of said spring for stopping the door closing movement of said carriage comprising an uninsulated conductor extending along the path of said carriage and a conductive part References Cited in the file of this patent UNITED STATES PATENTS 10 2,084,733 Kahlifi June 22, 1937 2,401.082 Konter May 28, 1946 2,544,239 Schirmer Mar. 6, 1951 2,589,480 Curtis Mar. 18, 1952 2,637,550 Ritter May 5, 1953 

